This invention relates to a novel spring shackle for pivotally supporting one end of a spring on a vehicle frame and a method of making the shackle. More specifically, this invention relates to a spring shackle and its method of assembly wherein an elastomeric bushing is employed without a conventional outer metallic sleeve; the elastomeric bushing having an inner metallic sleeve and being inserted directly into a cylinder formed by an end portion of the spring shackle for mounting the shackle to the frame member or spring.
This invention is in the nature of an improvement of the spring shackle disclosed in U.S. Pat. No. 3,030,101 which issued Apr. 17, 1962 to the present inventor. In accordance with the present invention, a spring shackle has a construction providing an end portion formed into a cylinder with a substantially continuous inner surface of substantially uniform radius. By means of this construction a spring shackle can employ an elastomeric bushing assembly without a conventional metallic outer sleeve and several advantages are achieved as set forth in the following objects and description of the invention.
One object of the present invention is to provide a spring shackle requiring fewer parts and having greater design flexibility than conventional spring shackles which employ standard "Silent Bloc" rubber bushing assemblies having metallic outer sleeves, which assemblies are available only in certain sizes. Another object of this invention is to provide a spring shackle more tolerant to slight variations in sizes of its component parts. A further object of this invention is to provide a method for easily and economically manufacturing a spring shackle. Still another object of this invention is to provide a spring shackle having a bushing assembly press fit directly into a cylinder wherein the bushing assembly resists rotation or other movement with respect to the cylinder.
These and other objects, features and advantages of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.